Systemic immune indicators for predicting renal damage in newly diagnosed type 1 diabetic children.

Background: Early kidney damage is a significant complication in children with newly diagnosed type 1 diabetes mellitus (T1DM). Systemic inflammation plays a key role in the development of diabetic nephropathy. Several inflammatory markers, including the systemic immune inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), have been proposed as potential indicators of diabetic complications.

Aim: To investigate the association between SII, NLR, PLR, and early kidney damage in newly diagnosed T1DM children without pre-existing albuminuria, assessing their utility as predictive biomarkers.

Methods: A longitudinal cohort study was conducted on 102 children aged 3-18 years with newly diagnosed T1DM [baseline urinary albumin-to-creatinine ratio (UACR) < 30 mg/g] recruited between January 2020 and June 2023. Participants were followed biannually for up to three years. Demographic, clinical, and laboratory data, including inflammatory markers (SII, NLR, PLR), were collected at baseline and follow-up. Logistic regression and receiver operating characteristic analyses were used to evaluate the predictive utility of these markers for early kidney damage, defined as UACR ≥ 30 mg/g.

Results: SII emerged as a significant independent predictor of early kidney damage [odds ratio = 1.002, 95% confidence interval (CI): 1.0008-1.0033, = 0.0016], with an area under the curve of 0.719 (95%CI: 0.612-0.826, < 0.001). Using an SII threshold of ≥ 624.015 achieved a sensitivity of 59.6% and specificity of 92%. Combining SII with NLR and PLR improved predictive accuracy (area under the curve = 0.787), with sensitivity and specificity of 63.5% and 96%, respectively. Correlation analyses revealed significant associations between SII, metabolic markers (triglycerides, glycated hemoglobin), and UACR.

Conclusion: SII is a reliable biomarker for early kidney damage in T1DM children, offering high specificity for identifying at-risk patients. Combining SII with NLR and PLR enhances diagnostic precision, supporting its integration into clinical practice. Longitudinal monitoring of these markers may facilitate early interventions to mitigate renal complications in pediatric T1DM.